Flutter app cannot make socket connection with certificate handshake error CERTIFICATE_VERIFY_FAILED

Question

One might say this question is a duplicate, but it is not, as other questions this type are about self-signed certificate, and about development environment.

I have a valid certificate from letsencrypt.org, but I cannot manage to establish socket connection. I have a nodejs server where I use the module "ws", and use the package "web_socket_channel" in flutter.

I had the same handshake problem for all my http requests (using requests package) but I could bypass it adding option verify to false:

 final r = await Requests.get(app_url, verify: false);

I don't like this solution as it is not secure for production environment. I would like a solution that would suit production environment.

Thanks to you all

Answer 1

For every one reading this, the problem was not from my flutter code, it was from my nginx configuration, I had to add the following lines to /etc/nginx/conf.d/sysmon.conf file:

location / {
        proxy_set_header   X-Forwarded-For $remote_addr;
        proxy_http_version  1.1;
        proxy_set_header    Upgrade $http_upgrade;
        proxy_set_header    Connection "upgrade";
        proxy_set_header    Host $http_host;
        proxy_set_header    X-Real-IP $remote_addr;
        proxy_set_header   Host $http_host;
        proxy_pass         http://<SERVER_IP>:<PORT>;
    }